• Asian-Australasian Journal of Animal Sciences
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• v.19 no.11
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• pp.1623-1631
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• 2006

The objective of this study was to evaluate the effect of protein and energy on goats fed oil palm fronds (OPF) as roughages. Twenty-four male Saanen goats aged between 7 and 8 months and weighing $23.4{\pm}1.6kg$ were used in a $2{\times}3$ factorial design. Factors were three levels of urea (3%, 4% or 5%) and two levels of energy (low energy (LE) or high energy (HE)). On average, all parameters measured, including dry matter intake (DMI), nutrient digestibility, digestible nutrient intakes, ruminal ammonia-N ($NH_3$-N), ruminal total volatile fatty acid (total VFA) and individual VFA concentrations (mM/L), microbial N supply, P/E ratio and N retention were higher for HE compared to LE diets. Significant (p<0.05) interactions were found between levels of urea and energy for nonstructural carbohydrate (NSC) and energy (DE) digestibilities, ruminal $NH_3$-N and total VFA concentrations. HE diets had higher N absorption and retention than LE diets. Interactions between urea and energy for plasma urea nitrogen (PUN), heat production (HP), and urine and faeces N excretion were significantly lower (p<0.05) for the HE diets than those recorded for the LE diets. The results indicated that supplementation of energy enhanced utilization of urea and resulted in higher animal performance as a consequence of improved ruminal fermentation, microbial yield and N balance. However, the optimal level of urea supplementation remained at 3% in the HE diet.

• Carbon letters
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• v.17 no.1
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• pp.1-10
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• 2016

Lignocellulosic biomass conversion to biofuels such as ethanol and other value-added bio-products including activated carbons has attracted much attention. The development of an efficient, cost-effective, and eco-friendly pretreatment process is a major challenge in lignocellulosic biomass to biofuel conversion. Although several modern pretreatment technologies have been introduced, few promising technologies have been reported. Microwave irradiation or microwave-assisted methods (physical and chemical) for pretreatment (disintegration) of biomass have been gaining popularity over the last few years owing to their high heating efficiency, lower energy requirements, and easy operation. Acid and alkali pretreatments assisted by microwave heating meanwhile have been widely used for different types of lignocellulosic biomass conversion. Additional advantages of microwave-based pretreatments include faster treatment time, selective processing, instantaneous control, and acceleration of the reaction rate. The present review provides insights into the current research and advantages of using microwave-assisted pretreatment technologies for the conversion of lignocellulosic biomass to fermentable sugars in the process of cellulosic ethanol production.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.4
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• pp.397-403
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• 2012

Galactose, an isomer of glucose with an opposite hydroxyl group at the 4-carbon, is a major fermentable sugar in various promising feedstock for hydrogen production including red algal biomass. In this study, hydrogen production characteristics of galactose-glucose mixture were investigated using batch fermentation experiments with heat-treated digester sludge as inoclua. Galactose showed a hydogen yield compatible with glucose. However, more complicated metabolic steps for galactose utilization caused a slower hydrogen production rate. The existence of glucose aggravated the hydrogen production rate, which would result from the regulation of galactose-utilizing enzymes by glucose. Hydrogen produciton rate at galactose to glucose ratio of 8:2 or 6:4 was 67% of the production rate for galactose and 33% for glucose, which could need approximately 1.5 and 3 times longer hydraulic retention time than galacgtose only condition and glucose only condition, respectively, in continuous fermentation. Hydrogen production rate, Hydrogen yield, and organic acid production at galactose to glucose ratio of 8:2 or 6:4 were 0.14 mL H2/mL/hr, 0.78 mol $H_2$/mol sugar, and 11.89 g COD/L, respectively. Galactose-rich biomass could be usable for hydogen fermenation, however, the fermentation time should be allowed enough.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.6
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• pp.648-653
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• 2018

Bran of barley causes high viscosity in bioethanol production due to the large amount of ${\beta}$-glucans and fiber. High viscosity is the main cause of decreased productivity and decreased facility efficiency in ethanol production. In order to prevent high viscosity, this study investigated the possibility of bioethanol from barley by debranning. As a result, it was able to reduced the viscosity (22.8 cP to 17.5 cP). And the fermentation speed and yield were improved as the activity of the enzyme and activity of yeast was also increased was improved due to the removal of non-fermentable components. In conclusion, debranning was advantageous in two ways. Firstly, bran removal increased the starch content of the feedstock and decreased viscosity of mash, improving ethanol fermentation. Secondly, by-products produced by debranning can use valuable products. It was remarkable results to the feasibility of bioethanol production from debranned barley.

• Animal Bioscience
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• v.36 no.5
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• pp.720-730
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• 2023

Objective: This study investigated the effects of corn silage as a source of microbial inoculant containing antifungal and carboxylesterase-producing bacteria on fermentation, aerobic stability, and nutrient digestibility of fermented total mixed ration (FTMR) with different energy levels. Methods: Corn silage was used as a bacterial source by ensiling for 72 d with an inoculant mixture of Lactobacillus brevis 5M2 and L. buchneri 6M1 at a 1:1 ratio. The corn silage without or with inoculant (CON vs MIX) was mixed with the other ingredients to formulate for low and high energy diets (LOW vs HIGH) for Hanwoo steers. All diets were ensiled into 20 L mini silo (5 kg) for 40 d in quadruplicate. Results: The MIX diets had lower (p<0.05) acid detergent fiber with higher (p<0.05) in vitro digestibilities of dry matter and neutral detergent fiber compared to the CON diets. In terms of fermentation characteristics, the MIX diets had higher (p<0.05) acetate than the CON diets. The MIX diets had extended (p<0.05) lactic acid bacteria growth at 4 to 7 d of aerobic exposure and showed lower (p<0.05) yeast growth at 7 d of aerobic exposure than the CON diets. In terms of rumen fermentation, the MIX diets had higher (p<0.05) total fermentable fraction and total volatile fatty acid, with lower (p<0.05) pH than those of CON diets. The interaction (p = 0.036) between inoculant and diet level was only found in the immediately fermentable fraction, which inoculant was only effective on LOW diets. Conclusion: Application of corn silage with inoculant on FTMR presented an antifungal effect by inhibiting yeast at aerobic exposure and a carboxylesterase effect by improving nutrient digestibility. It also indicated that fermented feedstuffs could be used as microbial source for FTMR. Generally, the interaction between inoculant and diet level had less effect on this FTMR study.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.6
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• pp.609-614
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• 2010

In the present study, bioethanol was produced using batch style reactor from food wastes which has organic characteristics. Pretreatment was required to reduce its particle size and produce fermentable sugar. Two different enzymes such as carbohydrase and gulcoamylase were tested for saccharification of food waste. The efficiency of carbohydrase saccharification (0.63 g/g-TS) has shown higher than glucoamylase saccharification(0.42 g/g-TS). Saccharomyces cerevisiae produced bioethanol via separate hydrolysis & fermentation (SHF) method and simultaneous saccharification fermentation (SSF) method. The production amount of bioethanol was 0.27 g/$L{\cdot}hr$ for SHF and 0.44 g/$L{\cdot}hr$ for SSF.

• Microbiology and Biotechnology Letters
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• v.43 no.1
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• pp.16-21
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• 2015

In this study, a facile two-step pretreatment method was investigated for producing fermentable sugars. Rice straw was pretreated using electron beam irradiation (EBI) and 4-methylmorpholine-N-oxide (NMMO) prior to enzymatic hydrolysis. In the first stage, the EBI on the rice straw was carried out at various doses (100, 300, 500 kGy) and then, irradiated rice straw was stirred with NMMO solution at 120°C for 1 h for the second stage. The pretreated rice straw was hydrolyzed by cellulase 1.5 L (70 FPU/ml) and Novozyme-188 (40 CbU/ml) at 50°C for 24, 48, and 72 h. A sugar yield of 83.8% was obtained from the pretreated rice straw after 72 h of enzymatic hydrolysis. Also, FTIR and XRD results indicate that the pretreatment of the rice straw was effective due to the synergic effects of the two-step pretreatment. In conclusion, rice straw might be a potential substrate for bioethanol production by yeast fermentation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.3
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• pp.539-549
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• 1996

Large bowel cancer correlates tightly to dietary factors such as dietary fiber and fat. Dietary fiber prevents the large bowel cancer in different modes of action which depend upon physicochemical and fermentable properties. Water-soluble fiber is fermented easily by intestinal microbes producing short chain fatty acids ; in contrast, water-insoluble fiber occurs effectively more rapid transit time due to greater bulk of gut content, though it is unfermentable. Not only short chain fatty acid is utilized in the proximal and distal colon as primary energy source, but also it lowers pH in the colon to normalize cellular differentiation and helps to stimulate peri staltic movement by acting as an osmotic laxative. In particular, butyric acid may also regulate gene expression and cell growth, though it is an important respiratory fuel for the colonocyte. Since dietary fiber and non-digestible oligosaccharides are the major source of butyric acid, this provides a possible link between dietary fiber and oligosaccharide and prevention of large bowel cancer. But, as with many links between dietary fiber and large bowel cancer, a direct casual association has not been established. In addition, RDA of dietary fiber which is 20~25g/day for adult Japanese, appears to be reasonable for the defecation once daily and the prevention of large bowel cancer.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.1
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• pp.1-9
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• 2016

The hydrolysis of biomass to fermentable sugar (saccharification) and to oligosaccharide is an essential process in biotechnology including biorefinery and biofood. Various macroalgae are commercially cultivated in several Asian countries as a useful resource for food and agar production. Agar is a major component of the cell walls of red algae that can be hydrolyzed by agarase. Agarases are classified into ${\alpha}$-agarase (E.C. 3.2.1.158) and ${\beta}$-agarase (E.C. 3.2.1.81) according to the cleavage pattern and grouped in the glycoside hydrolase (GH) family (GH-16, GH-58, GH-86, GH-96, and GH-118) based on the amino acid sequences of the proteins. Agarases have been isolated from various bacteria found in seawater and marine sediments. To increase productivity of the enzyme, a research on recombinant enzymes has been done. The application of recombinant agarase can be possible in the various filed such as energy, food, cosmetics, medical and so on. This paper reviews the source, biochemical characteristics and production system of recombinant agarases for further study.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.235-238
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• 2008

We examined butanol fermentation by Clostridium beijerinckii NCIMB 8052 using various hydrolyzates obtained from rice bran which is one of the most abundant agricultural by-products in Korea and Japan. In order to increase the amount of fermentable sugars in the hydrolyzates of rice bran, various hydrolysis procedures were applied. Total eight different hydrolyzates were prepared using rice bran (RB) and defatted rice bran (DRB) with enzyme or acid treatment and both. Each hydrolyzate was evaluated in terms of total sugar concentration and butanol production after fermentation by C. beijerinckii NCIMB 8052. Acid treatment yielded more sugar than enzyme treatment and combined treatment with enzyme and acid yielded even more sugars as compared to single treatment with enzyme or acid. As a result, the highest sugar concentration (33 g/L) was observed from the hydrolyzate from DRB (100 g/L) with combined treatment using enzyme and acid. Prior to perform fermentation of the hydrolyzates, we examined the effect of P2 solution containing yeast extract, buffer, minerals, and vitamins on production of butanol during the fermentation. Fermentation of the hydrolyzates with or without additionof P2 was performed using C. beijerinckii NCIMB 8052 in a 1 L anaerobic bioreactor. Although the hydrolyzates RB were able to support growth and butanol production, addition of P2 solution into the hydrolyzates significantly improved cell growth and butanol production. Highest butanol production (12.24 g/L) was observed from the hydrolyzate of DRB with acid and enzyme treatment after supplementation of P2 solution.